package com.th.review;

/**
 * @author ThreePure
 * @date 2022/5/23 16:06
 * @description: TODO
 * @since 1.8
 */
public class BookSale implements Saleable{
    public final int account = 100;
    @Override
    public int saled(int num) {
        if (num <= 100){
            return 100 - num;
        }else {
            return -1;
        }
    }
}
